1. Field of the Invention
The present invention relates to an open/close member control apparatus for opening/closing an open/close member such as a window in a vehicle.
2. Background Art
A window opening/closing control apparatus (hereinbelow, called “power window apparatus”) mounted on a vehicle is an apparatus for opening/closing a window by vertically moving a window glass in a door by rotating a motor forward or reverse in accordance with an operation of a switch. There is a power window apparatus having a manual mode of manually opening/closing a window and an automatic mode of automatically opening/closing a window. Japanese Unexamined Patent Application Publication No. 2001-118465 discloses an operation switch for a power window apparatus capable of switching five operation modes of a manual closing mode, an automatic closing mode, a manual opening mode, an automatic opening mode, and a neutral (stop) mode.
Generally, in the manual mode, a window closing or opening operation is performed only for the period of time in which an operation knob of a switch is manually held in the position of the manual closing mode or the manual opening mode. When the user moves his/her hand off the operation knob and the knob returns to the neutral position, the window closing or opening operation stops. On the other hand, in the automatic mode, once the operation knob is operated to the position of the automatic closing mode or the automatic opening mode, even when the user moves his/her hand off the operation knob and the knob returns to the neutral position, the window closing operation or the window opening operation continues.
In such a power window apparatus, in the case where an object or a human body is caught in the clearance of the window glass during the window closing operation, it is detected and the window closing operation is switched to the opening operation, thereby preventing the object or human body from being damaged and assuring safety. In particular, in the case of closing the window by the automatic closing operation, if there is no pinch detecting function, the window is continuously closed even after occurrence of a pinch. Consequently, from the viewpoint of avoiding danger, the pinch detecting function is indispensable.
When pinch occurs, the load on the motor for vertically moving the window glass upward increases and the rotation speed decreases, so that a change amount of the rotation speed of the motor increases. Therefore, the change amount of the rotation speed of the motor is compared with a predetermined threshold. When the amount of change does not exceed the threshold, it is determined that no pinch has occurred. When the amount of change exceeds the threshold, it is determined that pinch has occurred. In such a manner, whether pinch has occurred or not can be detected. Alternatively, by using the amount of change in current flowing in the motor in place of the amount of change in the rotation speed of the motor, whether pinch has occurred or not can be detected.
However, for example, when the window glass is frozen in winter and, due to this, the load on the motor increases in the window closing operation, although a foreign matter is not caught in the window, there is the possibility that occurrence of pinch is erroneously determined and the window is opened. As a countermeasure against the problem, Japanese Patent No. 3,157,011 discloses a technique that after occurrence of pinch is determined and a window is switched to the opening operation or stop, when a switch is operated to close the window, the window is forcedly closed. Japanese Unexamined Patent Application Publication No. S61-64983 discloses that, in the case where occurrence of pinch is determined, when it is detected that a switching operation of closing a window is performed a predetermined number of times, the window is forcedly closed. Further, Japanese Patent No. 3,578,568 discloses a technique of forcedly closing a window in the case where pinch of a foreign matter is determined a predetermined number of times in a row.
As described above, the power window apparatus can prevent an object or human body caught in a window from being damaged by providing the pinch detecting function. On the other hand, due to the existence of the pinch detecting function, the following problems arise.
For example, if a ruffian tries to enter a vehicle compartment from a window which is being closed in automatic closing operation, there is a case such that the closing window touches the body of the ruffian and occurrence of pinch is determined. The closing operation of the window is then switched to the opening operation, and the window is open. When the window is open, the ruffian can easily enter the compartment, and the driver may be harmed. Consequently, to prevent a ruffian from easily entering the compartment, it is performed that the window is not open even if pinch is detected in the case where the switch is operated to an automatic closing mode to close the window automatically and, after that, the switch is maintained in the automatic closing mode.
However, there is a case such that while the switch is maintained in the automatic closing mode against entry of a ruffian, the driver moves his/her hand off from the switch by mistake and the forced closing operation is cancelled. In this case, the switch is reset to a normal automatic closing mode. Hence, when pinch is detected, the window is open, and a ruffian can easily enter the compartment. There is another method of not opening the window but stopping the window when pinch is detected. In this case, however, although entry of a ruffian is suppressed, if an object is erroneously caught, the object remains caught. Therefore, if a pinch load is heavy, the object may be damaged.